Hypersensitivity and Induced Radioresistance in Chinese Hamster Cells Exposed to Radiations with Different LET Values

• Published in: International journal of molecular sciences 2022-06, Vol.23 (12), p.6765
• Main Authors: Koryakina, Ekaterina, Potetnya, Vladimir I, Troshina, Marina, Baykuzina, Raisa, Koryakin, Sergey, Lychagin, Anatoliy, Solovev, Aleksei, Saburov, Vyacheslav, Pikalov, Vladimir, Shegay, Petr, Ivanov, Sergey, Kaprin, Andrey
• Format: Article
• Language: English
• Subjects: Animals; Apoptosis; Bragg curve; Carbon; Cell cycle; Chinese hamster ovary cells; Chromosome Aberrations; Chromosomes; Communication; Cricetinae; Cricetulus; Cytogenetics; DNA damage; Dose-Response Relationship, Radiation; Dosimetry; Experiments; Fibroblasts; G1 phase; Gamma rays; Gamma Rays - adverse effects; hyper-radiosensitivity; induced radioresistance; Metaphase; Mutation; Neutrons; Proton beams; Protons; Radiation; Radiation therapy; Radioresistance
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms23126765

We study the impact of radiation LET on manifestation of HRS/IRR response in Chinese hamster cells ovary cells exposed to radiations used in radiotherapy. Earlier we have investigated this response to carbon ions (455 MeV/amu) in the pristine Bragg curve plateau and behind the Bragg peak, 60Co γ-rays, and 14.5 MeV neutrons. Now we present results of cytogenetic metaphase analysis in plateau-phase CHO-K1 cells irradiated with scanning beam protons (83 MeV) at doses < 1 Gy and additional data for 14.5 MeV neutrons. Dose curves for frequency of total chromosome aberrations (CA, protons), paired fragments (protons, neutrons), aberrant cells (neutrons) had typical HRS/IRR structure: HRS region (up to 0.1 and 0.15 Gy), IRR region (0.1−0.6 Gy and 0.15−0.35 Gy) for protons and neutrons, respectively, and regular dose dependence. Taken together with previous results, the data show that LET increase shifts the HRS upper border (from 0.08−0.1 Gy for γ-rays, protons and plateau carbons to 0.12−0.15 Gy for “tail” carbons and neutrons). The IRR regions shortens (0.52−0.4 γ-rays and protons, 0.25 plateau carbons, 0.2 Gy “tail” carbons and neutrons). CA level of IRR increases by 1.5−2.5 times for carbons as compared to γ-rays and protons. Outside HRS/IRR the yield of CA also enhanced with LET increase. The results obtained for different LET radiations suggest that CHO-K1 cells with G1-like CA manifested the general feature of the HRS/IRR phenomena.